Why no love for the 1/2 wave?

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jparks29

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I see everyone always mentions 5/8 or 1/4, and all but ignores the 1/2 wave for UHF or VHF.

1/2 wave gets out to the horizon a bit better than the 1/4, but still gets you up a little bit that you lose on the 5/8ths, so it's the best of both worlds, IMO..

Yet, no one mentions them or uses them.

What gives?
 

zz0468

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Because an end fed 1/2 wave antenna has a very high impedance and is more difficult to match than a 5/8 wave antenna.
 
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There are a few commerical 1/2 wave antennas around, Larsen used to sell one and GAM makes one of the best designs they are popular for sailboat use on mast tops but they can be used for conventional mobile use. Shakespere also sell one.
 

LtDoc

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The biggest differences between the various 'sizes' of antennas include the resulting radiation pattern of the 'sizes', and the ease of impedance matching. If one particular 'size' puts a signal where you want it to go then that's the one that would be most useful for you, right?
Then there's the 'looks' of the thing. Some are more 'tasteful' than others to some people. I won't comment on that aspect, too many possibilities.
Another aspect with that radiation pattern is the TOA, take off angle. Having a perfectly 'flat' radiation pattern that sends all signals off at the horizon would be nice. But, the 'flip-side' of that aspect is that all signals do NOT arrive at, or leave, an antenna at the lowest angle. Those TOA's vary from dang near horizontal to vertical, and there's no telling which one you are going to be listening to/for. :)
How do you know which would be bet for your particular application? You don't. So, try it and see. You are the only one who can say what works best in your particular situation. Trying for the lowest TOA isn't bad, but it isn't the solution in all cases.
- 'Doc
 

kayn1n32008

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1/4 and 5/8 wave tend to have a rather narrow bandwidth, which is fine if your operating in a narrow bandwidth. Where I work I can be, on Vhf, any where from 150-174Mhz and the antenna of choice IS a half wave because is has a very wide bandwith. Larsen, Sinclab and a few others do make 1/2 wave antennas, as well they do function a lot better with out a groundplane compared to either a 1/4 and 5/8 wave, hence they are much more popular when mounted on truck mirrors. In Alberta's oilpatch you are much more likely to see 1/2 wave antennas than any other just due to how spread out company and road channels are (literally ANYwhere between 148-174Mhz)
 

mrweather

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I use a 1/2 wave on my car. Not because I have groundplane issues but because it gives me a little more gain than a 1/4 wave and I can still garage park it without bending over the whip.
 

kayn1n32008

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Should have qualified that by adding 'compared to a 1/2 wave'
 
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